Process of making artificial mica sheets.



PATENTED MAR. 19, 1907.

B. COOPER. PROCESS OF MAKING ARTIFICIAL MIGA SIIEETS.

APPLICATION FILED JAN.10. 1907.

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Q Vi/hwoooo EdWaTd Cooper I 2 UNITED STATES PATENT OFFICE.

' EDWARD COOPER, OF NEWTON LOWER FALLS, MASSACHUSETTS.

- PROCESS OF MAKING ARTIFI IAL MICA SHEETS.

To all whom it may concern} I Be it known that I, EDWARD CooPER,'a citizen of the United States, residing at Newton Lower Falls, in the county of Middlesex and State of Massachusetts, have invented certain new and useful Improvements in Processes for Making Artificial Mica Sheets,

and I do declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use thesame'.

This invention relates to an improved rocess of manufacturing laminated mica s eets for use in electrical insulation.

The object of the invention isto provide a process for making laminated mica sheets in a rapid and economical manner whereby a great saving of labor is obtained,

In order that the details of my invention may be fully understood, the accompanying .drawings are described in connection there- The apparatus herein shown for carrying out this process comprises a tank 1 for containing a liquid cement suitable for this purpose, copal varnish or shellac being gener ally employed in which the dipping-basket 2 is to be immersed. This basket is preferably made of screen-wire having a mesh suf ficiently open to permit the cement to flow freely. therethrough, and yet prevent the scales from dropping out. The mica scales are first placed in the basket, and the basket is then immersed in the cement in the tank 1, whereby the scales are thoroughly coated with the cement. The basket is then elevated above the tank and so held to permit the surplus cement to run ofl the scales back into the tank. The scales are then removed Specification of Letters Patent. Application filed January 10, 1907- Serial No. 351,688-

Patented March 19, 1907.

from the basket and arranged on a perforated supporting-base, preferably made in the form of a wire screen 3, mounted in a frame 4 of Wood or any other suitable material. The first layer of the scales is arranged on the screen by taking several thicknesses ofthe scales at one time and arranging them in place without separating each scale, as heretofore. Another layer is then placed over the spaces found between the scales forming the first layer, as shown in Fig.3. Any desired number of layers are so arranged to form a sheet of thesdesired thickness. After the second layer is laid the screen is tilted into position (shown in Fig. 4) to permit the light to shine through in thin or weak using several thicknesses of mica scales at a time and not be required to separate each scale and arrange in' place, as in old process, on account of the Inica scales being thoroughly coated with cement, and a saving of places-in'the sheet being formed, so that the operator may reinforce these weak places by about sixty per cent. in labor is accomplished. The use of the wire screen or other perforated supporting-base for the cementcoated scales provides for the discovering of thin or weak places in the sheet being formed. There is no excess of cement after removing scales from basket.

I claim as my invention 1. The process of making laminated mica sheets which consists in first immersing the scales in a cement-bath, then draining the so immersed scales and arranging several thicknesses thereof in one operation on a perforated supporting-base, placing another layer of scales over the spaces of said first layer to break joint therewith, then tilting said perforated support into position to permit light to shine through thin or weak places in the sheet bein formed and then placing reinforpiing-sca es over the weak places so discovere 2. The process of making laminated mica sheets from scales which consists in first placing scales in a perforated basket and immel'sing it. in. u cemenbbznh. vlevzuing said i in testimony hereof l have hereunto set basket to drum surplus cement, from the 1 my hand In presence 01 two sulwsmwlnnx: wilseales, then urrnngmg' them on a wire screen messesv with. their edges emu-ed apart and in thei EIHVARI) COOPER. same plane and plzu-mg another izlyer 01 \\l,1.lles 1( s: scales over the spaces of SAM] first layer 10 g F. ('l n'lls.

break joint therewith. ClL-unJ-zs kx mm. 

